Induction of β-catenin correlates with a modulation of TCF1 isoform usage.

<p>(A) T cells were stimulated with plate bound anti-CD3 and anti-CD28 antibodies for the indicated times and immediately frozen as dry pellets on dry ice. Total cell lysates were prepared and run on SDS-PAGE, immunblotted for β-catenin, phospho-β-catenin and TCF-1. Total ERK expression served as a loading control. (B) T cells were fractionated based on the expression of CD4 and CD8 as well as CD45 isoform expression (CD45RA: naïve T cells or CD45RO: memory T cells) as outlined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012794#s4" target="_blank">materials and methods</a>. The cells were either left unstimulated or were stimulated overnight with anti-CD3/CD28 antibodies. Total cell lysates were immunoblotted for β-catenin and TCF1.